A computer, such as a server employed in operations, is generally connected to an uninterruptible power supply device that continuously supplies power when power supply has been interrupted in an emergency, such as a power outage. Data processing systems are also known that operate with plural computers having an interdependence relationship related to operation suspension that are connected to an uninterruptible power supply device. For example, in a data processing system operating with plural computers, a monitoring process is executed in each of the computers to monitor the uninterruptible power supply device. As an example of a monitoring process, when an interrupted state of power supply to the uninterruptible power supply device is detected in an emergency, such as a power outage, operation suspension processing of the computer is executed, and operation of the computer is suspended (so-called shutdown).
As an example of suspending operation of plural computers, technology is known in which a management device monitors an emergency power supply, such as an uninterruptible power supply device, and computers. In such technology, a user manually sets the management device with priorities for executing operation suspension processing of the computers. Technology employed in operation suspension processing of computers is also known in which plural application processes being executed on a single computer connected to the emergency power supply, such as an uninterruptible power supply device, are monitored, and these processes are stored in priority sequence. In such technology, in an emergency, such as a power outage, the execution sequence of programs is controlled such that processing is completed within the power supply time of the emergency power supply.
However, in data processing systems, when suspending the operation of plural computers having an interdependence relationship, a state needs to be avoided in which suspension of operation of the computers is not achieved within the power supply time of the emergency power supply. A fixed waiting time for power recovery is accordingly provided in each of the computers, and operation suspension processing is executed after the fixed waiting time for power recovery has elapsed.
For example, technology used in computer operation suspension processing is known that derives the power supply capacity, and the power supply available time, of an interruptible power supply device. In such technology, the time needed for operation suspension processing of one computer connected to an uninterruptible power supply device is subtracted from the power supply available time of the uninterruptible power supply device, and operation suspension processing is started at this time. Technology is also known for suspending power connection after operation suspension of a computer is completed, in which power connection to a computer is suspended when a communication result from an uninterruptible power supply device for a computer indicates a non-communication state. Technology is also known that sends a computer and peripheral devices connected to an uninterruptible power supply device commands to suspend operations, in sequence from the longest time needed for suspension.